29e5694054
Activate the RCU fast_gup for ARM64. We also need to force THP splits to broadcast an IPI s.t. we block in the fast_gup page walker. As THP splits are comparatively rare, this should not lead to a noticeable performance degradation. Some pre-requisite functions pud_write and pud_page are also added. [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Steve Capper <steve.capper@linaro.org> Tested-by: Dann Frazier <dann.frazier@canonical.com> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Cc: Hugh Dickins <hughd@google.com> Cc: Russell King <rmk@arm.linux.org.uk> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Mel Gorman <mel@csn.ul.ie> Cc: Will Deacon <will.deacon@arm.com> Cc: Christoffer Dall <christoffer.dall@linaro.org> Cc: Andrea Arcangeli <aarcange@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
123 lines
3.2 KiB
C
123 lines
3.2 KiB
C
/*
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* Based on arch/arm/mm/flush.c
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*
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* Copyright (C) 1995-2002 Russell King
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* Copyright (C) 2012 ARM Ltd.
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program. If not, see <http://www.gnu.org/licenses/>.
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*/
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#include <linux/export.h>
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#include <linux/mm.h>
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#include <linux/pagemap.h>
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#include <asm/cacheflush.h>
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#include <asm/cachetype.h>
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#include <asm/tlbflush.h>
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#include "mm.h"
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void flush_cache_range(struct vm_area_struct *vma, unsigned long start,
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unsigned long end)
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{
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if (vma->vm_flags & VM_EXEC)
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__flush_icache_all();
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}
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static void flush_ptrace_access(struct vm_area_struct *vma, struct page *page,
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unsigned long uaddr, void *kaddr,
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unsigned long len)
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{
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if (vma->vm_flags & VM_EXEC) {
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unsigned long addr = (unsigned long)kaddr;
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if (icache_is_aliasing()) {
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__flush_dcache_area(kaddr, len);
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__flush_icache_all();
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} else {
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flush_icache_range(addr, addr + len);
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}
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}
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}
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/*
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* Copy user data from/to a page which is mapped into a different processes
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* address space. Really, we want to allow our "user space" model to handle
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* this.
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*
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* Note that this code needs to run on the current CPU.
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*/
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void copy_to_user_page(struct vm_area_struct *vma, struct page *page,
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unsigned long uaddr, void *dst, const void *src,
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unsigned long len)
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{
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#ifdef CONFIG_SMP
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preempt_disable();
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#endif
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memcpy(dst, src, len);
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flush_ptrace_access(vma, page, uaddr, dst, len);
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#ifdef CONFIG_SMP
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preempt_enable();
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#endif
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}
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void __sync_icache_dcache(pte_t pte, unsigned long addr)
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{
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struct page *page = pte_page(pte);
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/* no flushing needed for anonymous pages */
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if (!page_mapping(page))
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return;
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if (!test_and_set_bit(PG_dcache_clean, &page->flags)) {
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__flush_dcache_area(page_address(page),
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PAGE_SIZE << compound_order(page));
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__flush_icache_all();
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} else if (icache_is_aivivt()) {
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__flush_icache_all();
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}
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}
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/*
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* This function is called when a page has been modified by the kernel. Mark
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* it as dirty for later flushing when mapped in user space (if executable,
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* see __sync_icache_dcache).
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*/
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void flush_dcache_page(struct page *page)
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{
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if (test_bit(PG_dcache_clean, &page->flags))
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clear_bit(PG_dcache_clean, &page->flags);
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}
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EXPORT_SYMBOL(flush_dcache_page);
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/*
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* Additional functions defined in assembly.
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*/
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EXPORT_SYMBOL(flush_cache_all);
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EXPORT_SYMBOL(flush_icache_range);
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#ifdef CONFIG_TRANSPARENT_HUGEPAGE
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#ifdef CONFIG_HAVE_RCU_TABLE_FREE
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void pmdp_splitting_flush(struct vm_area_struct *vma, unsigned long address,
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pmd_t *pmdp)
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{
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pmd_t pmd = pmd_mksplitting(*pmdp);
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VM_BUG_ON(address & ~PMD_MASK);
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set_pmd_at(vma->vm_mm, address, pmdp, pmd);
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/* dummy IPI to serialise against fast_gup */
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kick_all_cpus_sync();
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}
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#endif /* CONFIG_HAVE_RCU_TABLE_FREE */
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#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
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